Patent GB-597266-A (GB)
Title: Improvements in or relating to electric selective signalling systems
IPC: H02J13/00
Filed: 1943-12-24
Abstract: 597,266. Electric control and supervision. STANDARD TELEPHONES & CABLES, Ltd., McWHIRTER, E. M. S., and WARD, H. J. Dec. 24,1943, No. 21613. [Class 40 (i)] In a system which is described for the control and supervision of circuit-breakers at a number of sub-stations, but is applicable also for the control of lamps on an aerodrome, each substation comprises a number of similar selecting units SUA, SU, Fig. 25, which are arranged in ranks so that one unit of each rank responds to successive signals of a series to select a desired display and control unit DU, CU. As described, the signals are of three different kinds referred to A, B and C and are received over the common line SC by a translating unit STU2 which controls the units over a marking multiple. Thus each signal goes to all the units, but is effective only in the unit which has been selected by the preceding signal. The units SUA serve for the selection of the substation, SUA1 being responsive to a preliminary signal C and SUA2, 3 to signals B, A characteristic of the sub-station. The units SU each have 3 outlets, and as shown, two of the outlets from SU1 go direct to the first and last display units DU for use when a check on the condition of all the apparatus at the sub-station is required. Each selecting unit on responding to a signal causes a similar signal to be repeated back to the control station. The control station, Fig. 24, is provided with a set of keys AK and display units DU common to all the sub-stations and a sub-station selecting switch SSS, the line SC being connected to a translating unit STU1 similar to STU2. Selecting units SUA, SU arranged in ranks like those at the sub-stations are associated with STU1 over a marking multiple and each except SUA is linked with a routing unit RU. When the switch SSS has been set, any given key AK is connected to STU1 through a unique series of routing units which determine the signals to be sent for that selection. The preliminary signal is sent automatically, and in response to the return signal from the sub-stations SUA acts on RU6 to cause the sending of the first selecting signal and prepares SU6 for receiving the corresponding return signal. The operation continues in this manner, the sending of each signal being dependent on the reception of the preceding return signal, until the display unit DU associated with the operated key AK is connected up. A control signal depending on whether the key is moved to the ON or OFF position is then sent to bring about the desired operation in the selected control unit GU at the substation and DU responds to the return signal. Actuation of the key S'SK after the switch SSS has been set to select the sub-station causes signals to be sent back in succession from each of the display units DU at the sub-station indicative of its condition in response to' initiating signals from the control station, the indicating signals being distributed to the corresponding, unit DU at the control station. As described; all the signals are single impulses; but this is not essential. A 5-unit code might be employed, with converting apparatus of'the kind described in Specification 555,999. A pilot wire may be provided for signalling back any discrepancies between a control unit and the controlled apparatus. If the system is provided with more than one control station, the continuous passage of to-and-fro signals may be utilized to busy the common line, or alternatively a pilot wire between the control stations may be employed for this purpose. A brief description of the circuit operations is given below with reference to certain figures of the drawings. Selection and control. The actuation of key 14AK to the ON or OFF position causes the operation of one of three selecting relays in each of the routing units connecting it to SUA, Fig. 1. In the translating unit, STU1, Fig: 2, relays 2QS, 2X, 2C are normally operative and relay 2QB now energizes over wire H, which is connected to + by the operated selecting relay 3CB in RU6, Fig. 3, whereupon relay 2R operates to send the' preliminary C signal, consisting of - on both line wires, since 2C is up. Relays 2Z, 2ZA come up and 2QS relapses slowly and disconnects 2QB, 2R to end the signal. Relay 2QS re-operates and relay 1L is preparated by connection to wire H. In the substation translating unit STU2, Fig. 15, in which relays 15QS, 15X are normally operative, relays 15P, 15Q respond to the signal and connect up 15MA, 15MB, 15QA, 15QB, 15Z, 15ZA. The connection of + to wire H and - to wire F operates relay 16L in SUA1, Fig. 16, which connects up relay 16TC, followed by 15C. It should be noted that SUA1 responds only to a C signal ; if it were to respond also to A and B signals, further relays 16TA, 16TB would be provided, operable over wires TA, TB and these relays would control 15A, 15B over wires RA, RB. At the end of the incoming signal, relay 15R operates during the release time of 15QS, 15QA, 15QB to send a return signal consisting of + on both line wires, since 15C is up. This signal does not affect other sub-stations as relays 15P. 15Q are polarised. Relay 16TC remains locked to wire H, and the removal of - from wire F releases 16L which prepares 17LB in the next selecting unit SUA2, Fig. 17, by connecting it to wire H. Relay 15QS re-operates. In STU1 at the control station, relays 2P, 2Q respond to the return signal and connect up 2MA, 2MB, 2QA, 2QB, whereupon - on wire F operates 1L, which connects up 1TC and releases 2X, 2C. Since SUA is required to receive only a C signal, only the single relay ITC is provided. Relay 1TC closes a circuit prepared by the operated selecting relay 3CB in RU6 for relay 2B, so that at the end of the return signal 2R operates to send a B signal as the first selecting signal by applying - to the lower line wire. As before, 2QS, 2QA, 2QB fall back during the signal, relay 1L releases and prepares 4L in the next selecting unit SU6, leaving 1TC locked, and 2QS then re-operates. The receipt of this signal in STU2 energizes 17LB in SUA2, followed by 17TB, which disconnects 16TC and causes a similar signal to be sent back, whereupon 17LB falls back and prepares 17LA in the next unit SUA3. At the control station, the return signal in a similar way energizes 4L, 4TB, whereupon a circuit is made through the next routing unit RU8 for one of relays 2A ... 2C to control the sending of the next selecting signal, and the next selecting unit SU8 is prepared. The action continues until 23L is prepared by the final selecting signal and 14L by the subsequent return signal. If key 14AK is moved to the ON position, relay 2B energizes over wire RB and a B signal is sent to operate 23L, 23T and bring about the closure of the selected circuit-breaker. Relay 23SR energizes when this has taken place and causes a B signal to be sent back, 23T remaining locked. Relays 14L, 14T respond, and the latter locks and lights lamp 14LP. If key 14AK is moved to the OFF position, relay 2A energizes over wire RA and an A signal is sent, whereupon 23L releases 23T to open the circuitbreaker. The release of 23AR then returns an A signal which releases 14T and dims lamp 14LP. If desired, a second lamp may be lighted when 14LP is dimmed. The relapse of 2Z, 15Z when signals cease restores both translating units STU1, STU2 to their original condition. Checking conditions at a sub-station. Actuation of key SSK, Fig. 24, after the switch SSS has been set causes an A signal to be sent, after the preliminary and sub-station selecting signals, to connect up 21K in the first display unit DU at the sub-station. This relay prepares 21L, holds 21T in its then position and causes an A signal to be returned to operate the corresponding relay 13K at the control station, 13L being prepared. A B signal now energizes 21L which connects up 22K in place of 21K and applies + to wire RA or RB to send back an A or B signal according to the condition of 21SR, and the subsequent release of 21L prepares 22L. The indicating signal operates 13L, which connects 13T to wire TB so that it pulls up if the signal is of the B kind and lights lamp 13LP. Another B signal is sent to act on the second display unit at the sub-station, and so on until the conditions of all the circuit-breakers have been checked. Specification 597,325 also is referred to.